Swiss 7.5 GP11 vs 7.5 GP90

mikerock

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I am wondering what the differences were between the two cartridges? I understand that GP 90 has a case size of 53.5 mm or 54.5 mm, and the GP 11 is labelled as 55 mm. Is this the actual size or is it like the Finns calling their rifles 7.62x53?

I know the GP90 is loaded to a lower power, but do the cases need to be resized or can you use unmodified 7.5x55 brass?

Thanks
 
I am wondering what the differences were between the two cartridges? I understand that GP 90 has a case size of 53.5 mm or 54.5 mm, and the GP 11 is labelled as 55 mm. Is this the actual size or is it like the Finns calling their rifles 7.62x53?

I know the GP90 is loaded to a lower power, but do the cases need to be resized or can you use unmodified 7.5x55 brass?

Thanks

Are you asking this question because you want to make/replicate GP90 ammunition, or are you asking because you want to shoot GP11 in your Model 1889?

The first is highly possible, and many shooters do it.

The second is highy dangerous, and nobody with any sense would even try it once.

Read the ammunition description to be found in www.swissrifles.com

tac
www.swissrifles.com
 
What about the 1889/11 model rifles, would it be alright to use the GP11 ammo in those ?

I am curious as a friend gave me a whole bunch of GP11 1970s ish Swiss ammo and I have been interested in picking up a Swiss Model 1889/11 rifle to try it.
 
What about the 1889/11 model rifles, would it be alright to use the GP11 ammo in those ?

I am curious as a friend gave me a whole bunch of GP11 1970s ish Swiss ammo and I have been interested in picking up a Swiss Model 1889/11 rifle to try it.

Sir - I have never heard of a Model 89/11 - perhaps you mean a Model 96/11?

In which case, having had the gun checked over for the usual things that a gunsmith looks for to make sure that the arm is safe to shoot with the correct ammunition, you should be good to go.

My Model 96/11 has been a faithful shooter for me for many years - with GP11 and homeloads, too.

tac
www.swissrifles.com
 
Sorry, you are right tac, I got the model number mixed up :bangHead:. I was thinking of the Schmidt-Rubin 1889 rifles which I think should not be fed GP11 ?

I was looking at some the of the 1896/11s that Trade-ex has and it is very tempting to grab one.
 
What about the 1889/11 model rifles, would it be alright to use the GP11 ammo in those ?

I am curious as a friend gave me a whole bunch of GP11 1970s ish Swiss ammo and I have been interested in picking up a Swiss Model 1889/11 rifle to try it.

I have an 1896/11 and shoot GP11 no problem. It is my understanding that the 1911 upgrade was for the GP11.
 
Not successfully, too much pressure for that design.
Can only go up 30-40 Krag or 30-30Win pressure.

The 1896 could handle it with the/11 mods.
 
From Swissrifles.com

The Schmidt-Rubin Model 1889/96
(See picture of Model 1889)

Barrel Length - 30.7 inches: 3-groove, RH, concentric rifling, 1 in 10.63
Overall Length - 51.2 inches
Weight - 9.92lbs empty
Action - Schmidt-Rubin Straight Pull
Caliber - 7.5x53.5 Swiss (GP90 & GP 90/03)
7.5x54.5 Swiss (GP90/23)
Capacity - 12 round detachable box magazine
Sights - Quadrant sight graduated to 2000m
Total Production : 137,050
Bayonet: Model 1889, Model 1899, Model 1889/92, and Model 1906

Even before the Model 1889 entered service, the Swiss Rifle Technical Commission had reservations about the strength of the Model 1889s action. In 1888 they requested Col. Schmidt to redesign the Model 1889 action by moving the locking lugs forward on the bolt sleeve. However, Colonel Rudolph Schmidt, then the Director of Armament Manufacturing, refuse the request, claiming such a change was “not feasible.”

As the Model 1889 entered service, the Rifle Commissions fears were realized, yy 1892, it became apparent the rear mounted locking lugs of the Model 1889 were problematic. On November 3, 1892, Col. Vogelsang was assigned the task of designing three rifles with improved actions, shortly thereafter, and addition 50 rifles were requested

Col. Vogelsang’s, along with the assistance of his co-worker Rebholz, changes were fairly simple. In essence, here merely moved the locking lugs from the rear of the bolt sleeve to the front of the bolt sleeve. These changes weren’t quite that simple however, as it required a redesign of the bolt (including the bolt sleeve, firing pin and firing pin spring), receiver, and the stock.

Due to turnover amongst Armament Manufacturer Department Heads testing of the new action was delayed until 1895. On 1 January 1895, the test rifles were delivered to the shooting school in Walenstadt. Testing of the new design numerous improvements in performance.

Testing determined –
The bolt itself was strengthened,
Breakage of the locking lugs was reduced,
The action could handle higher pressure cartridges,
There was less binding of the bolt,
There was tighter lock-up of the bolt, producing better accuracy,
There was an increase in the length of pull, by 2cm, allowing for a better shooting position,
And there was a decrease in weight of about 100g,

It was determined that it would be impractical to attempt to convert the existing Model 1889s to the new action type, thus a new rifle model was required. Thus on July 31, 1896, a new rifle, designated the Model 1889/96 was approved for service.

Several minor modifications to the design were made throughout the service life of the rifle. Even before the rifle entered into production the barrel band and firing pin spring was redesigned and the rear of the receiver was widened slightly. Shortly thereafter, the firing pin itself was widened from 3.5 to mm in diameter.

Nearly all of the 1889/96 were converted into Model 1896/11 in the 1910s. Of the 137,000 89/96s produced, only 1,280 remained in their original configuration.
 
Are you asking this question because you want to make/replicate GP90 ammunition, or are you asking because you want to shoot GP11 in your Model 1889?

The first is highly possible, and many shooters do it.

The second is highy dangerous, and nobody with any sense would even try it once.

Read the ammunition description to be found in www.swissrifles.com

tac
www.swissrifles.com


I am asking for reloading purposes, thanks.
 
Many do not bother trimming the 55mm brass down to 54 or 53.5mm since it does not make any difference in the chamber, so long as all your brass is trimmed the same way for consistent internal chamber pressure.

Of course, If you only have K31 specific dies, and brass fired in K31s, you'll have a real problem getting the brass to fit the original size chambers.

I use three sets of regular 7.5x55 dies for everything.
 
Many do not bother trimming the 55mm brass down to 54 or 53.5mm since it does not make any difference in the chamber, so long as all your brass is trimmed the same way for consistent internal chamber pressure.

Of course, If you only have K31 specific dies, and brass fired in K31s, you'll have a real problem getting the brass to fit the original size chambers.

I use three sets of regular 7.5x55 dies for everything.


Thank you, this is what I was looking for. I have some unfired norma brass. I can load it to 7.5x53.5 specs with 7.5x55 dies and then it will fire form to the chamber?
 
Thank you, this is what I was looking for. I have some unfired norma brass. I can load it to 7.5x53.5 specs with 7.5x55 dies and then it will fire form to the chamber?

Precisely.
FL sizing dies. Fireforming should not be need. No not use too slow a powder or you will get sooty necks. You need to seal the necks quickly because you have quite a bit of space around them. Crimping is a good idea too. A lit bit of wax around the neck will help too. Just like the pre-1978 GP11 had.

Another Montrealer, Mezigot is his tag, has done quite a bit of work on this, here is one of his post.
http://forums.gunboards.com/showthread.php?157091-7-5x53-5-Swiss-reloading.
 
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